SQL Server has default value for fill factor is Zero (0). The fill factor is implemented only when the index is created; it is not maintained after the index is created as data is added, deleted, or updated in the table. When creating an index, you can specify a fill factor to leave extra gaps and reserve a percentage of free space on each leaf level page of the index to accommodate future expansion in the storage of the table’s data and reduce the potential for page splits. Let us learn about how to change default fill factor of index.
The EXCEPT operator returns all of the distinct rows from the query to the left of the EXCEPT operator when there are no matching rows in the right query. The EXCEPT operator is equivalent of the Left Anti Semi Join. EXCEPT operator works the same way NOT IN. EXCEPTS returns any distinct values from the query to the left of the EXCEPT operand that do not also return from the right query.
Index optimization is always interesting subject to me. Every time I receive requests to help optimize query or query on any specific table. I always ask Jr.DBA to go over following list first before I take a look at it. Most of the time the Query Speed is optimized just following basic rules mentioned below. Once following checklist applied interesting optimization part begins which only experiment and experience can resolve.